1. Field Of The Invention
The invention relates to a new process for the production of 3,5-dichloro-2-pyridone, which, on its part, can easily be converted to 2,3,5-trichloropyridine.
2. Prior Art
2,3,5-Trichloropyridine forms an educt in great demand for the production of a wide range of insecticides [P. Sutter et al., J.Het.Chem. 17, 493 (1980)].
The production of 3,5-dichloro-2-pyridone in a yield of 63 percent by chlorination, starting from 2-pyridone is known [Cava et al., J. Org. Chem. 23, 1614 (1958)]. According to U.S.S.R. Pat. No 194,823 (Appl. 4/20/1966), it is also known to obtain 3,5-dichloro-2-pyridone in mixture with 5-chloropyridone starting from 2-pyridone by reaction with tert-butyl hypochlorite.
But these known processes have the drawback that, in each case, it is necessary to start with relatively expensive 2-pyridone.